SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0383e658f75157a16e6194202f69f723332d43ad0c0fe2dc12ef6b5a0652b896' 
  AND token = 'z/K4BtYFwJnyDM+AkDbeuIEwxWN65nEShqmMHCi7gKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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