SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f847b016a09ad2dcbe4130ec7f70b92531a337de2dd2d7972f425227853b4880' 
  AND token = 'ZfzaeAK+5sOyouX0VtacgAoWOAt8PwaL5TXtb96dcGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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