SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24e958479ae37143b7091c3253eb2ca8e9fccc4c6b396cf25f42583e513e2f2c' 
  AND token = 'zXv9Is3C/rkSwpyI8hzNjOaxVQGixVoXLbda5Kegv7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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