SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b9a214f6c3c8a03a72a800f50ab730be22410cb660b24cee13fa54677402af0' 
  AND token = 'jk2qlbErNkoAmHG8Ra4wqG9Kt1qI5kxCEcf8EX/K4Zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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