SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '262ae4270b6dfb4143dce3f81d474a80fdf404a42d16f1653cfb588bb5bebb19' 
  AND token = 'TACVRxtw6TJVb1xiHOjj92JlojAGe5tSX+Cu2jjC1II=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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