SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a98055ad9d2cdd3b969fdd18a45aacc21049fe53d7cbf2fb795bfddada34e481' 
  AND token = 'UzbqKPt0DWLXcY+t9xMiOWZykOhXjH/J4Bic8v2DhGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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