SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '990366fe4e2af4d00a8a7f95242117cfa80603769d6dec9e68fc496bd9c23417' 
  AND token = 'Zz/mTTxPkiWbVe9p0ipSoemQxwteOpNJ99npWKKxE8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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