SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a4c082952b8b1a3746eef57935207dbd64c23dee7dbce66321e7486a0f55e57' 
  AND token = 'efSqwFsqNMGFyQIrxXtgy7gnA68iFuREz/lSiE9oTco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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