SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03556a56c22b7bb17ccd20cbdc4fc534a4320c17dbfd076ac5618263f44a3e1a' 
  AND token = 'XFxAMCcq0o9rjQOW1jzY08GBc6Kf+C8qzyogWc0By5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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