SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '649ad41736b573174dc96a0a06cbd2d85400593ae20f944756f6c23ebaffc38d' 
  AND token = 'iZHBIbirA2qHHQR4bkMtpWxBivazYfZf2BoaRw52pDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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