SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '552b0e9705f5c200f042036965e9e4f52d45c90b48700a662f6cadd1f9fadbc2' 
  AND token = 'amRao3lUZNKffv+vlmG/c2yMArSDIdd+iY7q35WnpKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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