SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f40620a4ff96936561694a4585039a9415e22ed989f0a3f372d608ba266cf5d' 
  AND token = '9eWk411upH4uGc4f7GmMqRHcUflj1v1H3tOPe/5EraE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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