SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8972237078c34576e84033ccd1ecc50b2d7228d520780cdbb5dd0575cf78834' 
  AND token = 'ZA8+8tvfUEgtupSqw6ce25DMgXYEKkrJyEv4gG1mkd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

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