SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d504792fcf37df29df5a62a87d25e07ae39b345805b58ab21dc029e4fd1f1d' 
  AND token = 'nwV9+Q16/8HgEvcHPoigG3rnaBd2NAsUBj6wHVtq6VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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