SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6a6c4719871fcfbea79d45038d9cdee9b26321910ed85a0fa0b1131d7b124bc' 
  AND token = 'hGne7Ip6HgGJbJBynJC38Bwr6Qfs5AF/MiaYZNV9fsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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