SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '607ca819ed39c46968f586ef1d447d54473eb1b114cc6fcc281aab08aaf089c4' 
  AND token = 'lMSrW3ea6tZ3oDm2mOOpHsPOfrM/qMAye7M0DGjsPd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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