SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a52f8f735368558cafbb4f149f771d02736965fc9890949eea2d89d2998e8c3' 
  AND token = 'W03PW3JZM68qrqClMMwfMCJGvOXsY6YVRVTHUAnDl3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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