SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '08b37ead306da445b8d31ac7347572af7514805df08ad994724c4329bb052750' 
  AND token = 'iJK/xGCFpcFj+NA9mugvYyVytkIe8ch5Hx6FANNCmNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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