SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeb6f8af428e0c40216c85328129788f1686b371761e8db29611dadb86d0c4b5' 
  AND token = 'rSBFfKbHZzWZDU2EJ89oCEbrc8UUTGUx1lhPJfAUf48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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