SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f153f75c34652c476a00f575474f88b26530543276b92e8fdcbeaff3bba24ef' 
  AND token = 'iZA7mNzogV8bVXfHvxEeEelseo78iJyLt4QzWXnjxA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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