SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9f940d94229f34c93ee990e52221a768534ff4052f658832a0f654ddac66b98' 
  AND token = 'tbLU7eiK6EOPO2oeHdG4SZnIAplnAOY3WjpnApZi3nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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