SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8e7a7cc42460d1319087e17d94b7808b9a4e810568cf99cc6a2df5c911429376' 
  AND token = 'aORx6QJfIRYtjopaSFceVMcjlP3dWfnC1A16jw+4xSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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