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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76512245186af10ffe1dfefb273c36e65b1dd81b732e9c0c4bf9f087aa3000c9' 
  AND token = '9bvAnpQwLAGEwfr20LKVq2XBPskk7oWuGYwEDiH04ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

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