SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0869cf51fd86c82746e3f90ca1edc1e249e17184dd72493b37ddd5ce778365a9' 
  AND token = 'RNvCvrzLDOb+UJIkNkIQZEx3bR3Ip4TBcqTMxfTVjZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}