SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4f4f723f03e27a1fd927b9ac43625632110ecd58ce1a0f1d4b86033f5722c9b' 
  AND token = '1fnCwixb1HjrytiHD8SEULTwUeemGsvHwsXQoUuiaqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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