SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd5787296b53b95c76c34223dcea12ddc565304ba65f3cf28b51d09501d77ca3' 
  AND token = 'Lpx4BoWrEWxnEiRlugnPLtqkxJ4AInS7eH8lvWnAHEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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