SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed3f48f9d202ab6cf3f6ace5e7da17632a631c9afa21bc53c1e7ea3535f571f1' 
  AND token = 'CPOIUuPOzqeNEMNbN2lFFI/qId7euOWz56G6A5c6QU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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