SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ed8ebf5348167722ce241b33c636107fb9333e3acafa5bcdb89cfc1e6f4aab' 
  AND token = 'QTntBgN/G1xZg9qCSbu4WtTgofGe0k7PvzVdjWj1DBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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