SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6280031c75ebd4e587ccfd82081edeab01f7d90cf2c3a16e6cd7b9f85bb7f52e' 
  AND token = 'kFG4oN9ILfw7hqM8d8fMPw7P8mlgDOVzQS/E5AH8oSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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