SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa303bf46d76ff44fac7e4b5940814250250ddbb6f4b61825269776841e1bda' 
  AND token = 'sVtoz232iT/gLR9RY51u3q2JCC5twBEYLmzkLL6MWFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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