SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09cfe1607448e5b543774aeb59ff3773ea25cbd0c964b3ac91112f5dd16a461' 
  AND token = '5NjOUOb3Q0M3Kp/X5XDecTD+XNxE9RaIno4H+TOPAyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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