SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a82955a8d511f2efbf741d825c42e794adf4138d8188e84835fed1a99960d0c3' 
  AND token = 'TkEkr1NUyuyawBIptFCjUYOdad5LjjK9QZsPPLfTpz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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