SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '190251cbc42397618ef333efe9922873c22ce43b0e1629b0d39da6f2c828044a' 
  AND token = 'yPVzN5i1vxGPD8LCXOiS48z9VFO7tN1QRXidGjk393U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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