SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53aaa0e709872f922421a0f1364dfc809170bff5b47aff5428fa3f8cb52408f3' 
  AND token = 'baF9oJ8LcyzpqpMW0mSnOAo1ABFXffXbmM6folyx28U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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