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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b01c99127b261a9df17b8fbca53ca3ecd024fe59eaf0e0801641cd7eb4cfbfcc' 
  AND token = 'u5HsrZsSDVwdtdHRXMPvoJQyXOk07HQtuVpfql8CXd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE								Impossible WHERE noticed after reading const tables