SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5493b0cdba7c2492274cd2add2824e2004320235320e5c6dd4ac0ca96fab885e' 
  AND token = 'z7z9bsLPl5djuuPgTuSl9vwBakre+cTHGWfQp16KudE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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