SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8bd464755803eef1239d16a162cefc15a9bf2df15bba128845f79e33131616d' 
  AND token = 'woB89Io6BztBYzuLsGV1YOvlF4wSx+qcTmgSqdhIJHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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