SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fe41f003c080090ef27ab6ecc121efb54acbc39aab96de29c7363c9b77627a5' 
  AND token = 'TPkq6/gt5ZhBf5Huzgov5/T1j2KNmDL11GO8wmG2h+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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