SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b552345d2e32c7a825e57b88da2cb38e610690277584c2541760d92684900502' 
  AND token = 'AILSfiS3Xg4gL8KXdN2jZGwIraR7RhjMJr7dFc1TKZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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