SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10e7c3dc6f347002d29569055c5d6a8f54303b38debb15cce5ae44dd0617b45d' 
  AND token = 'XDNawb9qwlIlxLLYq91FLiOIoxx1CDuzlCkByOtLBv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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