SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eac56c3fb684dbbc84fdf9909092765fe33280165162b0beac2ff5f441fe3ba1' 
  AND token = 'LKu67lXkzxRA5CtATIq1FLeHwZbXYYPWCTmM/wKO0Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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