SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf918969d678ed4f7587afd0a2009083f64ec3adc8641bd51265255f7112d634' 
  AND token = 'FlbcsnbFCb31suYF+n80AoFzuRZX/7WE9RQDVJShi1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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