SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f108b92d59a4be4f5d9756ba85f54a6979b2136707ff2894105a07f0411882da' 
  AND token = 'EwjyUvRSai0X+2BG/bopsZZVyouQxtUW45Q/KB7/k7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}