SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32374ccb5686ef64c4de9e49be6adb026870153ff6e4c3191dd94fcde27cc455' 
  AND token = 'K0FcP7jwRSGHK7UJaRzgXRaiU1oL1pNfDJY9ImQGH0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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