SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8380067b55b6fe56b5dfeb98488c9b1a57169cc3dda8b8620a8ed52fc40c1da4' 
  AND token = 'bfifJye187wWC7U+KmDcbR5erbypbOe6x0m9GN1/K7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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