SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09ec149d2eda1eb21a5201e06f977a75fcd272104925aa8cdecb9585a007997f' 
  AND token = 'YxjRT/a53auFhStyC3HHQENDdRxUYsIlOEsm5ENHYv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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