SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bee9e1683513e3a75de17acd9ad97eb344269e6a283834303370929f4cfa4431' 
  AND token = 'JJYUyozIEPs7BBqFbqTFrC8+BW+dS/PC5deRqDYQg7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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