SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e619681d4a9d1269f4f886a1c49cb68744cd8912b0d06738b4ab0754c2cc5631' 
  AND token = 'jHfrdhuSgZfaxW8JIQPkjnKVw3ZLV/6PAKH+4e0WcVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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