SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7fadf6087ec934f7948659d6e1375935d92a3766a092b3908c26fa5784f1e201' 
  AND token = 'w56lXvN4Fx521cH4uS7HYkXTxHgUEfgXDJCuCaZzSww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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