SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0c1461a3c1c0869eea8bddfcf9668021c5738e0606d81cc10549af9247d3ac6' 
  AND token = 'URUus/QPgWF98v4w/iUx+3GiPZUZBKTwOpeAGW1tvU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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