SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '803f7c434f3e05ab6299203b364cc8423c359e30fab219ecb309054de49aa34e' 
  AND token = 'x47QqNIqnfDA9sqZ8AxXP7+KhnbaX9Mze03wSpX+tKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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