SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13f2d08f87041c03e9ac95c7ba0c1e653e15a90e9538ceacb4e652696eccf690' 
  AND token = 'Gow2EEWmYk+/tsR3Win8QO3LGg1ZmORtZ8qRQsV3mQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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