SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b6b5d650b72a602a34888db4689404b4f9a117da7ad0afdd99e5331b59085c78' 
  AND token = 'V35B00Vc+FB7RsKVC+m+cW9r5W26LHr9t9N6xHAP5cI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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