SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5211c65b5b0e614a4f8b51766de9233b541f4d3e76c719052409f59cf96fd159' 
  AND token = 'P0c7BOTPgYAQ0jGqKJdn+Mc1kXvAjoLoiD9lJOIybxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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