SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb561aa55137e0eb710e5ec44121e15c40b3236dcc886cb518ed0606147db0a6' 
  AND token = 'SXAcUdgGj4DX7UCwONrFBbVIAA7yzHAhF6Dx9aWEcKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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