SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b487a17634371afcd0520a5541dafebe459ce0698820d562f0aa557b70dac9b' 
  AND token = 'Ctg3Ng1/uTxHduI70lnUTYL6OF2vSNB8Aq8hsdQG99Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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