SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8f092f6748f5f201dae389a7346e1bca7b6fe99eb445412f9c2880686380626' 
  AND token = 'hvpXHJUYtkJSxIN+qugSSJ3nN+/2iRcMqZd+HUwgrYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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