SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38750553df2a2d8b994edba78dd219474b8b66225eb4cdf912545c46cfa7d542' 
  AND token = 'BSh/5GYN7hdW2gXX99cG3rBfu3ainFUY/+gXRinqFFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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