SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b8a5005d002490daff1fd62467f9a0bb09b0aa3b4e7486aa633deea17a3a8b0' 
  AND token = 'o4daBU5QwSCpnbgecLmlz0pJGFg6Lg3FVdfVKhELnAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}