SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5213b1ce1374e1d02055f062188ae4de91cb548cdca098380e214dacbf86af3f' 
  AND token = 'OffCDzp3ztiyG9iusE3lt85OiF16993UL4YvIByoSpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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