SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2ae32938f6075e01ecd72369444a868d4ea77a7c83d72a98cd2a81958965697' 
  AND token = 'pe9yMBGH/ovtITbxVtmwWP/SaJicolYZTWK9+pRtg6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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